Merge pull request #2 from ThomasDebrunner/read-api

Add nice data access API

.gitignore

@@ -379,3 +379,4 @@ pyrightconfig.json
 .ionide
 
 # End of https://www.toptal.com/developers/gitignore/api/c++,meson,sonar,python,sonarqube,visualstudiocode,clion
+.idea

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.24 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.22 FATAL_ERROR)
 
 project(ulog_cpp LANGUAGES CXX)
 

examples/ulog_data.cpp

@@ -8,7 +8,6 @@
 #include <string>
 #include <ulog_cpp/data_container.hpp>
 #include <ulog_cpp/reader.hpp>
-#include <variant>
 
 int main(int argc, char** argv)
 {
@@ -44,26 +43,71 @@ int main(int argc, char** argv)
   }
 
   // Read out some data
-  // TODO: create a simpler API for this
-  const std::string message = "multirotor_motor_limits";
-  printf("%s timestamps: ", message.c_str());
-  for (const auto& sub : data_container->subscriptions()) {
-    if (sub.second.add_logged_message.messageName() == message) {
-      const auto& fields = data_container->messageFormats().at(message).fields();
-      // Expect the first field to be the timestamp
-      if (fields[0].name != "timestamp") {
-        printf("Error: first field is not 'timestamp'\n");
-        return -1;
-      }
-      for (const auto& data : sub.second.data) {
-        auto value = ulog_cpp::Value(
-            fields[0],
-            std::vector<uint8_t>(data.data().begin(), data.data().begin() + sizeof(uint64_t)));
-        printf("%lu, ", std::get<uint64_t>(value.data()));
-      }
+
+  // List all subscription names
+  auto subscription_names = data_container->subscriptionNames();
+  for (const auto& sub : subscription_names) {
+    std::cout << sub << "\n";
+  }
+
+  // Get a particular subscription
+  if (subscription_names.find("vehicle_status") != subscription_names.end()) {
+    const auto& subscription = data_container->subscription("vehicle_status");
+
+    // Get message format of subscription
+    auto message_format = subscription->format();
+    std::cout << "Message format: " << message_format->name() << "\n";
+
+    // List all field names
+    std::cout << "Field names: "
+              << "\n";
+    for (const std::string& field : subscription->fieldNames()) {
+      std::cout << field << "\n";
+    }
+
+    // Get particular field
+    auto nav_state_field = subscription->field("nav_state");
+
+    // Iterate over all samples
+    std::cout << "nav_state values: \n";
+    for (const auto& sample : *subscription) {
+      // always correctly extracts the type as defined in the message definition,
+      // gets cast to the value you put in int.
+      // This also works for arrays and strings.
+      auto nav_state = sample[nav_state_field].as<int>();
+      std::cout << nav_state << ", ";
     }
+    std::cout << "\n";
+
+    // get a specific sample
+    auto sample_12 = subscription->at(12);
+
+    // access values by name
+    auto timestamp = sample_12["timestamp"].as<uint64_t>();
+
+    std::cout << timestamp << "\n";
+  } else {
+    std::cout << "No vehicle_status subscription found\n";
+  }
+
+  if (data_container->messageFormats().find("esc_status") !=
+      data_container->messageFormats().end()) {
+    const auto& message_format = data_container->messageFormats().at("esc_status");
+    std::cout << "Message format: " << message_format->name() << "\n";
+    for (const auto& field_name : message_format->fieldNames()) {
+      std::cout << field_name << "\n";
+    }
+  } else {
+    std::cout << "No esc_status message format found\n";
   }
-  printf("\n");
 
+  if (subscription_names.find("esc_status") != subscription_names.end()) {
+    auto esc_status = data_container->subscription("esc_status");
+    for (const auto& sample : *esc_status) {
+      std::cout << "esc_power: " << sample["esc"][7]["esc_power"].as<int>() << "\n";
+    }
+  } else {
+    std::cout << "No esc_status subscription found\n";
+  }
   return 0;
 }

examples/ulog_info.cpp

@@ -54,23 +54,28 @@ int main(int argc, char** argv)
   printf("Dropouts: %zu, total duration: %i ms\n", dropouts.size(), total_dropouts_ms);
 
   auto print_value = [](const std::string& name, const ulog_cpp::Value& value) {
-    if (const auto* const str_ptr(std::get_if<std::string>(&value.data())); str_ptr) {
-      printf(" %s: %s\n", name.c_str(), str_ptr->c_str());
-    } else if (const auto* const int_ptr(std::get_if<int32_t>(&value.data())); int_ptr) {
-      printf(" %s: %i\n", name.c_str(), *int_ptr);
-    } else if (const auto* const uint_ptr(std::get_if<uint32_t>(&value.data())); uint_ptr) {
-      printf(" %s: %u\n", name.c_str(), *uint_ptr);
-    } else if (const auto* const float_ptr(std::get_if<float>(&value.data())); float_ptr) {
-      printf(" %s: %.3f\n", name.c_str(), static_cast<double>(*float_ptr));
-    } else {
-      printf(" %s: <data>\n", name.c_str());
-    }
+    std::visit(
+        [&name](auto&& arg) {
+          using T = std::decay_t<decltype(arg)>;
+          if constexpr (std::is_same_v<T, std::string>) {
+            printf(" %s: %s\n", name.c_str(), arg.c_str());
+          } else if constexpr (std::is_same_v<T, int32_t>) {
+            printf(" %s: %i\n", name.c_str(), arg);
+          } else if constexpr (std::is_same_v<T, uint32_t>) {
+            printf(" %s: %u\n", name.c_str(), arg);
+          } else if constexpr (std::is_same_v<T, float>) {
+            printf(" %s: %.3f\n", name.c_str(), static_cast<double>(arg));
+          } else {
+            printf(" %s: <data>\n", name.c_str());
+          }
+        },
+        value.asNativeTypeVariant());
   };
 
   // Info messages
   printf("Info Messages:\n");
   for (const auto& info_msg : data_container->messageInfo()) {
-    print_value(info_msg.second.field().name, info_msg.second.value());
+    print_value(info_msg.second.field().name(), info_msg.second.value());
   }
   // Info multi messages
   printf("Info Multiple Messages:");
@@ -82,35 +87,18 @@ int main(int argc, char** argv)
   // Messages
   printf("\n");
   printf("Name (multi id)  - number of data points\n");
-
-  // Sort by name & multi id
-  const auto& subscriptions = data_container->subscriptions();
-  std::vector<uint16_t> sorted_subscription_ids(subscriptions.size());
-  std::transform(subscriptions.begin(), subscriptions.end(), sorted_subscription_ids.begin(),
-                 [](const auto& pair) { return pair.first; });
-  std::sort(sorted_subscription_ids.begin(), sorted_subscription_ids.end(),
-            [&subscriptions](const uint16_t a, const uint16_t b) {
-              const auto& add_logged_a = subscriptions.at(a).add_logged_message;
-              const auto& add_logged_b = subscriptions.at(b).add_logged_message;
-              if (add_logged_a.messageName() == add_logged_b.messageName()) {
-                return add_logged_a.multiId() < add_logged_b.multiId();
-              }
-              return add_logged_a.messageName() < add_logged_b.messageName();
-            });
-  for (const auto& subscription_id : sorted_subscription_ids) {
-    const auto& subscription = subscriptions.at(subscription_id);
-    const int multi_instance = subscription.add_logged_message.multiId();
-    const std::string message_name = subscription.add_logged_message.messageName();
-    printf(" %s (%i)   -  %zu\n", message_name.c_str(), multi_instance, subscription.data.size());
+  for (const auto& item : data_container->subscriptionsByNameAndMultiId()) {
+    printf(" %s (%i)   -  %zu\n", item.first.name.c_str(), item.first.multi_id,
+           item.second->size());
   }
 
   printf("Formats:\n");
   for (const auto& msg_format : data_container->messageFormats()) {
     std::string format_fields;
-    for (const auto& field : msg_format.second.fields()) {
-      format_fields += field.encode() + ", ";
+    for (const auto& field : msg_format.second->fields()) {
+      format_fields += field->encode() + ", ";
     }
-    printf(" %s: %s\n", msg_format.second.name().c_str(), format_fields.c_str());
+    printf(" %s: %s\n", msg_format.second->name().c_str(), format_fields.c_str());
   }
 
   // logging
@@ -127,11 +115,11 @@ int main(int argc, char** argv)
   // Params (init, after, defaults)
   printf("Default Params:\n");
   for (const auto& default_param : data_container->defaultParameters()) {
-    print_value(default_param.second.field().name, default_param.second.value());
+    print_value(default_param.second.field().name(), default_param.second.value());
   }
   printf("Initial Params:\n");
   for (const auto& default_param : data_container->initialParameters()) {
-    print_value(default_param.second.field().name, default_param.second.value());
+    print_value(default_param.second.field().name(), default_param.second.value());
   }
 
   return 0;

examples/ulog_writer.cpp

@@ -4,7 +4,6 @@
  ****************************************************************************/
 
 #include <chrono>
-#include <cstdint>
 #include <string>
 #include <thread>
 #include <ulog_cpp/simple_writer.hpp>

test/CMakeLists.txt

@@ -1,19 +1,27 @@
 
 
 include(FetchContent)
+
+set(SYSTEM_ARG SYSTEM)
+# cmake < 3.25 fails with system attribute
+if (CMAKE_VERSION VERSION_LESS "3.25")
+	set(SYSTEM_ARG "")
+endif ()
 FetchContent_Declare(
-	DocTest
-	GIT_REPOSITORY "https://github.com/doctest/doctest.git"
-	GIT_TAG "v2.4.11"
-	SYSTEM
+		DocTest
+		GIT_REPOSITORY "https://github.com/doctest/doctest.git"
+		GIT_TAG "v2.4.11"
+		${SYSTEM_ARG}
 )
 
+
 FetchContent_MakeAvailable(DocTest)
 
 
 add_executable(tests
     main.cpp
     ulog_parsing_test.cpp
+    read_api_test.cpp
 )
 
 target_link_libraries(tests PUBLIC